Edge bending press

ABSTRACT

Disclosed is an apparatus for bending a workpiece while retaining the same in a single plane. An exemplary use for such an apparatus is to bend a flat sheet of steel prior to blanking and forming operations and preparatory to its being assembled into a vehicle frame. Such an operation, referred to in the art as edge bending is known to conserve materials but is difficult to achieve with prior art devices and therefore has not been widely adopted. The present apparatus overcomes many of the problems with the prior art devices. It includes a base and a bed member parallel to and movable toward and away from the base. One or more push blocks are supported by the bed and guided for movement transversely thereof. A linkage is provided to move the push blocks across the bed as the bed is moved toward and away from the base. The apparatus is designed for operation with a conventional hydraulic or mechanicam press and the bed is moved toward the base by the press. The apparatus allows conversion of a conventional stamping press to an edge bending press. The ram of the press need only be fitted with a flat plate which, in conjunction with the bed of the present apparatus serves to restrain the workpiece in the desired plane.

United States Patent 1191 Bowman, Jr. et al.

[451 Sept. 30, 1975 1 1 EDGE BENDING PRESS [75] Inventors: MilesAugustus Bowman, Jr.,

Reading; Christopher James Hampton, Boyertown; Paul Henry Schock,Reading. all of Pa.

[73] Assignee: Dana Corporation, Toledo, Ohio [221 Filed: Dec. 2, 19741211 Appl. No.: 528,616

Primary E.\'aminerC. W. Lanham Assistant Examiner-Gene P. CrosbyAttorney, Agent, or Firm-Robert E. Pollock [57] ABSTRACT Disclosed is anapparatus for bending a workpiece while retaining the same in a singleplane. An exemplary use for such an apparatus is to bend a flat sheet ofsteel prior to blanking and forming operations and preparatory to itsbeing assembled into a vehicle frame. Such an operation, referred to inthe art as edge bending is known to conserve materials but is difficultto achieve with prior art devices and therefore has not been widelyadopted. The present apparatus overcomes many of the problems with theprior art devices. It includes a base and a bed member parallel to andmovable toward and away from the base. One or more push blocks aresupported by the bed and guided for movement transversely thereof. Alinkage is provided to move the push blocks across the bed as the bed ismoved toward and away from the base. The apparatus is designed foroperation with a conventional hydraulic or mechanieam press and the bedis moved toward the base by the press. The apparatus allows conversionof a conventional stamping press to an edge bending press. The ram ofthe press need only be fitted with a flat plate which, in conjunctionwith the bed of the present apparatus serves to restrain the workpiecein the desired plane.

14 Claims, 4 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 GM3,908,435

US. Patent Sept. 30,1975 Sheet 2 of4 3,908,435

Sept. 30,1975 Sheet 3 of 4 US; Patent Sheet 4 of 4 Patent Sept. 30,19753,908,435

xi so EDGE BENDING PRESS 7 BACKGROUND OF THE INVENTION This inventionrelates to material bending tools and more particularly to such toolsadapted to bend a workpiece in a single plane.

In certain manufacturing operations it is desirable to deform a sheet ofmaterial laterally between the planes defining the top and bottom facesthereof. Typical of such operations is bending sheets which aresubsequently formed into vehicle frames. Such a forming procedure isknown in the art as edge bending and will be so referred to hereinafter.Although principally applied in metal forming it is apparent that edgebending can be employed with any yieldable material which can bepermanently deformed.

Presses for edge bending have been available for some time. US. Pat. No.1,340,138 which issued May 11, 1920 to H. Miller illustrates one suchpress.

While generally satisfactory, such edge bending presses have certainshortcomings. A major drawback to known edge bending presses is thatthey are adapted only to such service and cannot be readily modified'toserve as conventional stamping presses.

Further, many of the prior art edge bending presses exert substantialunbalanced lateral forces and therefore require massive restraintmembers to transmit the unbalanced lateral forces from the movable ramto the fixed bed of the machine. Such members often obstruct clearpassage of the formed material through the machine.

It is, therefore, an object of the present invention to provide an edgebend press which is readily convertible to a conventional stampingpress.

It is a further object of the invention to provide tooling which can beinstalled in a conventional stamping press to convert the same for anedge bending operation.

It is another object of the invention to provide an edge bend system inwhich the lateral forces are substantially balanced thereby minimizingthe size of the structural members required for a given bendingoperation.

It is still another object of the invention to provide such a mechanismwhich allows unobstructed removal of the workpiece upon initialseparation of the ram and bed.

SUMMARY OF THE INVENTION The above and other objects are achieved in theedge bending press apparatus of the present invention. The pressincludes a base and a bed member generally parallel to the base. Guidemeans are provided to allow the bed member to move toward and away fromthe base and prevent other relative movement (e.g., cooking and lateralmovement) therebetween. At least one and generally a plurality of pushblocks are supported by the bed member, extend thereabove and are guidedfor movement transversely thereof. A linkage means is providedconnecting the base of each of the push blocks to move the push blockstransversely of the bed as the bed moves toward and away from the base.

Such a device can simply be placed within a conventional stamping pressof appropriate size and power. The base of the device rests on the bedof the press. A flat platen mounted to the press ram contacts the bed ofthe device during operation to transmit the forces necessary to move thelinkage transversely.

In a preferred embodiment the linkage means comprises a lever means.Such a linkage is not only mechanically simple, but also, in the contextof the present invention, provides an increasing force asv such a forceis required at the limits of the bending.

A further preferred feature of the invention is the use of plural pushblocks with alternate ones thereof operating in opposition. Such anarrangement, particularly when used in combination with a lever typeactuator balances the lateral forces and generally allows the use ofmembers in tension or compression thereby reducing the requisite mass ofthe apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes withclaims which particularly point out and distinctly claim the subjectmatter forming the present invention it is believed that the same willbe better understood with reference to the following description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a partial schematic isometric view of a preferred embodimentof the invention;

FIG. 2 is a vertical cross-sectional view of the invention generallycorresponding to a view taken along line 22 in FIG. 1;

FIG. 3 is a vertical cross-sectional view generally corresponding toFIG. 2 showing the apparatus in its final working position, and;

FIG. 4 is a plan view, from above, of the apparatus of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to the drawings,FIG. 1 thereof illustrates a preferred embodiment of the invention in apartially schematic form suited to the ready understanding thereof. Thebasic support for the apparatus is a base designated generally by thenumeral 10 which is adapted for support on the table of a generallyconventional stamping press. A bed member, designated generally by thenumeral 20 is guided and supported, as will hereinafter more fully bedescribed, so as to be movable toward and away from the base 10 whileremaining parallel thereto. Such support is primarily provided by guidemembers, designated generally by the numeral 30, which extend upwardfrom the base 10 along the vertical faces of the bed 20.

Preferably the base 10 defines a plurality of apetures 11 through whichtravel cushion pins 12. Such pins are generally conventional in stampingpresses equipped with cushions and serve to minimize shock loading andcontrol the rate of application of press force. Normally in using theapparatus of the present invention to adapt a stamping press to edgebending duty the cushion pin arrangement and control can be retained;the pins need only be modified in length as may be required for aparticular application. An apeture 11 is associated with each pin andthe bed 20 may include pockets or the like to receive the pins. Thepresent invention can also include a yieldable support in the base ofthe tooling to allow the use thereof in a press not provided withcushions.

The bed supports one or more push block's, designated generally by thenumeral 21, ivhich, in the illustrated and preferred embodiment iIiEludesll 'e members 22 and forming blocks 23. The upper face 24 of the bedmember 20 is preferably made of hard steel and the slide member 22 istherefore preferably hard faced steel or faced with a material such asbronze or an alloy thereof which slides readily thereon. As will be seenand hereinafter more fully described the material to be formed rests onthe slide members 22 and the same are moved laterally in the directionof the arrows as the bed 20 moves relative to the base 10 uponapplication of press pressure.

Any suitable means can be provided to cause the push blocks to movelaterally upon relative motion between the bed member 20 and base 10.The preferred means is a link arrangement comprising links 25 which arepivotally connected to the base 10 via pins 26 and to the push blocks bysimilar pins (not shown). Such a linkage means is not only very simplebut also, in the present apparatus configuration, provides a highlydesirable mechanical advantage as will hereinafter and more fully bedescribed.

In the preferred embodiment. multiple push blocks are used and alternateones thereof move laterally in opposite directions. Such an arrangementminimizes or eliminates altogether any net lateral force in theapparatus and thereby eliminates the need for any additional means forproviding lateral stability. The push blocks 21 can be of any desiredwidth and various ones of the blocks can be of different widths withinthe apparatus. Both the widths of the push blocks 21 and the geometry ofthe forming blocks 23 will, of course, be dictated by the final desiredconfiguration of the bent workpiece. Spacer blocks designated generallyby the numeral 40 are preferably but optionally provided betweenalternate ones of the push blocks 21. The spacer blocks 40 serve toguide the push blocks 21 and also serve in conjunction with the slidemembers 22 to support the workpiece. Plates 41 are provided in lateralspaced relationship at either end of the spacer blocks 40 to maintainthe requisite spacing between the ram plate and forming blocks 23 toprevent excessive friction therebetween.

The apparatus shown in FIG. 1 is placed on the table of a press and theram of said press is provided with a flat platen so sized as tosubstantially cover the bed 20. The workpiece is put in place atop thespacer blocks 40 and push blocks 21 and the press ram is lowered. Uponcontacting the plates 41 and forming blocks 23 the press platen forcesthe bed 20 and associated structure downwardly against the urging of thecushion pins. The workpiece is maintained against vertical deformationby the clamping pressure between the press platen and the upper surfacesof the slide members 22 and spacer blocks 40. In this connection, itshould be noted that the forming blocks 23 and plates 41 are preferablyslightly greater in thickness than the material to be formed therebyassuring that such members transmit all of the vertical forces on thepress while not providing clearance between the press platen and thetops of the slide members 22 and spacer blocks 40 of such size as toallow substantial vertical deformation of the workpiece.

As the press platen continues downward the push blocks 21 move laterallyin the direction of the arrows as a result of the action of the linkmechanisms.

FIG. 2 of the drawings is a detailed vertical cross sectional view ofthe apparatus of FIG. 1 taken generally along the line 22. A block 13 isaffixed to the base 10 by any suitable means such as bolts 14 andprovides a support for the pins 26. The bed 20 preferably includes topplate 24 and bottom plate 26, side plates 28 and intermediate supportsin the form of vertically oricnted eye-beams 29. The bed 20 is slottedlaterally to accommodate the depending portion of the slide member 22which receives the pin 26. The platen 50 preferably includes areplacable wear plate 51 affixed thereto by any suitable means such asbolts 52. The preferred material for the wear plate 41 is hard steel.Similar wear plates can also be provided on the bed 20 adjacent to andsupporting the slide members 22.

With continuing reference to FIGQ 2, the bed 20 is held at the upperextreme of its travel by the cushion pins 12 prior to the actuation ofthe press and lowering of the ram and platen 50. While the bed 20 is inthis position. the workpiece W is placed thereon and between theopposing forming blocks 23. For ease of loading the forming blocks 23are. at this time, widely separated relative to the width of theworkpiece W and the links 25 are at an angle 0 of about 60 from thehorizontal. The angle 0 can, of course be varied from machine to machineas desired to provide the preferred force/distance relationship for anyapplication. Furthermore multiple positions for pins 26 in blocks 13 maybe provided for adjustability.

The guide members shown diagramatically in FIG. 1 preferably take theform of vertical members 31 supported on the base and extending in pairson either side of each of and closely adjacent to each of a plurality oflateral extensions 32 on the sides of the bed 20. Such an arrangementallows the bed to move freely toward and away from the base 10 whilesubstantially eliminating any other relative movement therebetween.Replacable wear plates can be provided on the vertical members 31 orabutting portions of the bed 20 as may be required in any particularapplication.

FIG. 3 shows the apparatus in the position it assumes at the end of thetravel of the platen 50. At this point the links are at an angle 0 ofabout to horizontal. Although not critical, it is preferred that theangle 0 be from about 20 to As will be recognized the link mechanismprovides a force multiplication effect which is highly desirable. Forinstance, if the final angle 0' is 30 the force multiplication (ignoringfriction) is 3; i.e., equal to the contangent of 0. Reduction in theangle 0 rapidly increases the final force multiplication. Further itwill be noted that as the bending nears completion and the bending forcerequirement is at its maximum, the angle 0 approaches its minimum andthe contangent reaches its maximum value. The apparatus, therefore,provides the maximum bending force concurrent with the maximum needtherefor.

FIG. 4 is a plan view of the apparatus of FIG. 3 with the platen 50removed for clarity. As shown, the apparatus includes four push blocks21 and five spacer blocks 40 although it will be appreciated that anynumber of such elements can be employed. In forming relatively longworkpieces such as components for vehicle frames a plurality of unitssuch as that shown in FIG. 4 will be used and to that end connectionmeans in the form of cutouts 60 are provided on the sections to allowthem to be connected to one another by suitable clamps to form a longintegral unit. It will be recognized that such an approach provides aready means to modify the overall apparatus to allow the use of commonparts in setups for related finished parts.

As can be seen the forming blocks 23 can be flat, angular or curved inplan view to achieve the desired final shape of the workpiece. Furthereach push block 21, with its associated forming block 23, and eachspacer block 40 can be any desired width.

What is claimed is:

1. An apparatus for bending a workpiece in a single plane comprising abase, a bed member generally parallel to said base, guide means topermit said bed member to move toward and away from said base andprevent other relative movement therebetween, a push block supported byand extending above said bed and guided for sliding motion transverselythereof and linkage means connecting said base and said block to movethe latter across said bed as said bed is moved relative to said base.

2. The apparatus of claim 1 wherein said linkage means comprises a levermeans.

3. The apparatus of claim 1 having a plurality of push blocks, each pushblock havinga linkage means said linkage means being so arranged as tomove alternate ones of of said push blocks in opposite directions.

4. The apparatus of claim 3 wherein said linkage means comprises a levermeans.

5. The apparatus of claim 1 additionally including cushioning meansconnected to said bed and extending through said base.

6. The apparatus of claim 5 wherein said linkage means comprises a levermeans.

7. The apparatus of claim 5 each having a linkage means said linkagemeans being so arranged as to move alternate ones of said push blocks inopposite directions.

8. The apparatus of claim 7 wherein said linkage means comprises a levermeans.

9. The apparatus of claim 1 wherein said push block comprises a slideportion and a shaped forming portion and said slide portion rests onsaid bed.

10. The apparatus of claim 9 including a plurality of push blocks andspacer blocks fix interposed therebetween and fixed to said bed.

11. The apparatus of claim 9 wherein said linkage means comprises alever means.

12. The apparatus of claim 9 each having a linkage means said linkagemeans being so arranged as to move alternate ones of said push blocks inopposite directions.

13. The apparatus of claim 12 wherein said linkage means comprises alever means;

14. The apparatus of claim 13 including a plurality of push blocks andspacer blocks interposed therebetween and fixed to said bed.

1. An apparatus for bending a workpiece in a single plane comprising abase, a bed member generally parallel to said base, guide means topermit said bed member to move toward and away from said base andprevent other relative movement therebetween, a push block supported byand extending above said bed and guided for sliding motion traNsverselythereof and linkage means connecting said base and said block to movethe latter across said bed as said bed is moved relative to said base.2. The apparatus of claim 1 wherein said linkage means comprises a levermeans.
 3. The apparatus of claim 1 having a plurality of push blocks,each push block having a linkage means said linkage means being soarranged as to move alternate ones of of said push blocks in oppositedirections.
 4. The apparatus of claim 3 wherein said linkage meanscomprises a lever means.
 5. The apparatus of claim 1 additionallyincluding cushioning means connected to said bed and extending throughsaid base.
 6. The apparatus of claim 5 wherein said linkage meanscomprises a lever means.
 7. The apparatus of claim 5 each having alinkage means said linkage means being so arranged as to move alternateones of said push blocks in opposite directions.
 8. The apparatus ofclaim 7 wherein said linkage means comprises a lever means.
 9. Theapparatus of claim 1 wherein said push block comprises a slide portionand a shaped forming portion and said slide portion rests on said bed.10. The apparatus of claim 9 including a plurality of push blocks andspacer blocks fix interposed therebetween and fixed to said bed.
 11. Theapparatus of claim 9 wherein said linkage means comprises a lever means.12. The apparatus of claim 9 each having a linkage means said linkagemeans being so arranged as to move alternate ones of said push blocks inopposite directions.
 13. The apparatus of claim 12 wherein said linkagemeans comprises a lever means.
 14. The apparatus of claim 13 including aplurality of push blocks and spacer blocks interposed therebetween andfixed to said bed.